Filament winding and composite materials have been a desirable substitute for metals and other materials in manufacturing applications. Composite materials have the advantages of being high strength, lightweight, and easily formable. Composite materials are comprised of a fiber, typically carbon, that is impregnated with a curable resin. Composite materials are often drapable like a fabric, allowing the uncured composite material to be formed into various shapes. Once the composite material is in the desired shape, the resin is cured and hardened to create a rigid structure.
Despite the many positive characteristics of composite materials, the overall cost of composite materials often makes their use impractical. Various factors affect the cost of composite materials. One factor is the number of manufacturing steps required in order to form a composite structure. Often manufacturing a composite material and forming the composite material into the desired shape requires multiple machines and extensive hand labor. For example, one method of creating a composite material is to weave fibers into a sheet of composite material. Weaving large sheets of carbon fibers can require expensive machines and can be a time intensive process.
Furthermore, impregnating a composite material with a resin adds additional steps to the process. These additional steps can involve impregnating entire sheets of composite materials with resins, creating difficulties in uniformly applying a resin to a large sheet of composite material. Additionally, these impregnating processes are often performed by different manufacturers at different locations, adding manufacturing and shipping costs at each step. As a result, the overall price of the composite materials for the end user can be high.
Another shortcoming of composite materials is the amount of hand labor required when assembling a composite structure. Often, multiple layers of composite materials are required in order to make a structure, and different orientations of composite materials are needed. In many current processes, each individual layer of composite material is laid up and oriented by hand onto a form or other shaping structure. The process of laying up and orienting individual sheets of composite material can add further expense and time to the already expensive and time-consuming manufacturing process.
Yet another problem with current composite materials is the handling of the resin impregnated composite material. In many applications the resin is made to have a low viscosity in order to allow resin to flow between the individual fibers of the material. The resin may be provided in a liquid form at ambient temperatures. While low viscosity resin allows for better permeation of the composite material, a low viscosity of liquid resin creates undesirable handling characteristics. Furthermore, the low viscosity resin does not effectively maintain the lay up of the composite sheet. Thus, the fibers may separate and fall apart when being handled or transported. Also, a low viscosity resin may flow away from certain sections of the composite material while being cured, leaving some areas with insufficient resin.
Therefore, what is needed in the art is an inexpensive composite material that eliminates the costs inherent in the composite manufacturing process. It would be an advancement in the art to provide a composite material impregnated with a resin that is solid or semi-solid at ambient temperatures. It would also be an advancement in the art to provide a composite material that is manufacturable in multiple layers and with multiple fiber orientations.
It would be another advancement in the art to provide a process that eliminates manual assembly steps in forming composite structures by creating a significant portion of a composite structure while manufacturing the composite material. Furthermore, it would be an advancement to provide a composite material that prevents the resin from uncontrollably transferring to objects that come in contact with the material or from flowing out of the uncured composite material. It would be another advancement in the art to provide a composite material with desirable tack and drape characteristics for forming the composite material into a desired shape. Such apparatuses and methods are disclosed and claimed herein.